fn main() {
    test1();
    println!("-------------------------");
    test2();
    println!("-------------------------");
    test3();
    println!("-------------------------");
    test4();
}
fn test1() {
    //let x = 5;
    let mut x = 5;
    println!("The value of x is: {x}");
    x = 6;
    println!("The value of x is: {x}");
}
fn test2() {
    const THREE_HOURS_IN_SECONDS: u32 = 60 * 60 * 3;
    println!("The value of THREE_HOURS_IN_SECONDS is: {THREE_HOURS_IN_SECONDS}");
}
fn test3() {
    let x = 5;
    let x = x + 1;
    {
        let x = x * 2;
        println!("The value of x in the inner scope is: {x}");
    }
    println!("The value of x is: {x}");
}
fn test4() {
    let spaces = "    ";
    let spaces = spaces.len();
    //let mut spaces = "    ";
    //spaces = spaces.len();
    println!("The nums of spaces: {spaces}");
}

